In many textile machines, it is necessary to have some sort of a thread or yarn severing device. This is particularly so in the case of shuttleless looms, such as air and water jet looms like the Elitex air jet loom. For cutting certain types of threads a mechanical device is essential, and such mechanical cutting devices usually comprise scissors elements, or chisel and anvil cutting components. For instance for Elitex air jet looms designed for weaving glass yarn, a cutting mechanism is provided comprising two blades that operate in a scissors motion to cut the yarn as it completes an insertion cycle on the loom. While such cutters are operational, they are relatively expensive to maintain, requiring frequent resharpening, and being expensive to replace, the entire cutting mechanism being replaceable.
There have been proposals in the art recognizing advantages in avoidance of wear associated with chisel and anvil cutting mechanisms, as described in U.S. Pat. Nos. 3,951,179 and 2,007,485. However, either the chisel-like elements associated with such prior proposals have not been readily replaceable, or are not designed for utilization with some types of shuttleless looms, or they are not easily retrofit onto or finely adjusted on such looms.
According to the present invention, a thread severing mechanism in general, and in particular a shuttleless loom utilizing a thread severing mechanism, are provided having numerous advantages. Utilizing the thread severing mechanism according to the present invention on a conventional shuttleless loom, such as an Elitex air jet loom, costs associated with maintaining the severing mechanism are reduced by several orders of magnitude. Further, the thread severing mechanism according to the present invention is conveniently positioned on a conventional loom on pre-existing loom structures with a minimum of modification, yet effectively and efficiently performs its intended operation. When maintenance is necessary, however, component parts of the severing mechanism may be readily replaced.
According to one aspect of the present invention, a thread severing mechanism is provided which comprises the following elements: A cutting blade having a razor edge. An anvil having a thread supporting surface, the thread supporting surface including a block of material having the blade-protection and thread-severing-facilitating properties of rubber. And, means for effecting movement of the blade with respect to the anvil thread supporting surface so that the blade razor comes in contact with the thread supporting surface, severing any thread supported thereon. Additionally, means are provided for readily detachably mounting the blade to the means for effecting movement thereof so that the blade may be readily replaced when the razor edge thereof does wear out. This detachable means may comprise a threaded end of a shaft and a pair of internally threaded nuts, one disposed on either side of the blade, abutting the blade, and in screw-threaded engagement with the shaft. The shaft may comprise a component part of the means for moving the blade, which means further includes a bushing for mounting the shaft for rotation about an axis generally perpendicular to the blade, and an actuator operatively associated with the shaft at a portion thereof remote from the blade, for effecting rotation of the shaft about its axis.
The anvil is mounted so that its position with respect to the cutting blade may be varied, and such mounting means may comprise an elongated slot formed in a portion of the anvil and a threaded fastener extending through the slot. The fastener is positioned and dimensioned so that when it is tightened down to a supporting surface the anvil is held in place with respect to the supporting surface, and when it is not tightened down the anvil is movable with respect to the supporting surface with the fastener sliding within the elongated slot. The anvil thread supporting surface is mounted on a portion of the anvil generally perpendicular to the anvil portion having the elongated slot, and a fabric guide extends outwardly from that portion of the anvil.
According to another aspect of the present invention, a shuttleless loom is provided with an improved thread severing mechanism. The loom includes means for inserting thread in an insertion cycle into the loom, and has a portion thereof, which includes a temple, adjacent the area of insertion of the thread. The thread severing mechanism comprises an anvil having a thread supporting surface, a cutting blade having a razor edge, means for mounting the anvil on the temple, and means for effecting movement of the blade with respect to the anvil thread supporting surface so that the razor edge comes in contact with the thread supporting surface, severing any thread supported thereon. The anvil mounting means previously described mounts the anvil on the temple, the threaded fastener being received by a threaded opening formed in the temple. A fabric guide means may comprise a rod extending outwardly from the anvil generally parallel to the temple, and prevents the fabric from riding up on the thread supporting surface of the anvil. The blade movement effecting means preferably is as previously described, and may be readily retrofit into many existing loom yarn severing actuator structures.
It is the primary object of the present invention to provide an efficient and inexpensive thread severing mechanism, particularly for a shuttleless loom. This and other objects of the present invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.